In a system using a credit card, a cash card of a bank, and the like, an owner (patron) of the card is identified by identification (ID) information such as a membership number, a name, a position, and the like printed on the card. At the same time, the identity of a user is confirmed, in other words, identification operation is carried out by a PIN number or a password which an operator (user) of a card reading terminal inputs.
With the progress of information technology in recent years, on the other hand, the information technology of not only a system developer but also an antisocial organization abusing it is advanced, fraudulent transactions by card theft, forgery, and PIN number decipherment are rapidly increased.
As measures for them, the technology of encrypting information printed on the card and the like, the technology of biometric identification using biometric information such as a fingerprint and an iris pattern, and the like are developed.
The publication of Japanese Patent No. 3475304, for example, discloses an IC card which holds security information in the form of a hologram or the like in contrast to magnetically recorded ID information.
Japanese Patent Laid-Open Publication No. 2001-67399 discloses an identification system which sends biometric identification information to an IC card to carry out validation.
In the foregoing IC card disclosed in the publication of Japanese Patent No. 3475304, an image into which the security information is encoded is stuck on the IC card as the hologram. There is a problem that the security information is easily extracted from the hologram when an encoding scheme is stolen.
Also in the case of the IC card of the Japanese Patent Laid-Open Publication No. 2001-67399, there is a problem that the identification information can be extracted from the IC card when an algorithm for encoding data is recognized.
Furthermore, in an identification system by the ID card like described above, using high cryptographic technology can increase safety but, on the other hand, the amount of data processing and an infrastructure necessary for carrying out the system become large and hence convenience is reduced. Thus, a tradeoff occurs between safety and convenience.